The following description of the background of the invention is provided simply as an aid in understanding the invention and is not admitted to describe or constitute prior art to the invention.
Dehydroepiandrosterone (DHEA) [(3β-hydroxy-5-androsten-17-one)] is a weak androgen synthesized by the adrenal cortex. It has a short plasma half-life and is usually converted to dehydroepiandrosterone sulfate (DHEA-S). Excessive DHEA secretion can produce acne, hirsutism and virilization via conversion to testosterone.
Mass spectrometric methods for measuring DHEA in a sample have been reported. See, e.g., Chatman, K., et al., Anal Chem 1999, 71:2358-63; Liu, S., et al., Anal Chem 2003, 75:5835-46; Higashi, T., et al., J Chromatogr B 2007, 195-201; Hsing, A., et al., Cancer Epidemiol Biomarkers Prev 2007, 16:1004-8; Labrie, F., et al., J Steroid Biochem Mol Biol 2007, 107:57-69; Guo, T., et al., Arch Pathol Lab Med 2004, 128:469-75; Guo, T., et al., Clinica Chemica Acta 2006, 372:76-82; and Zou, P., et al., Food Addit Contain 2007, 24:1326-33. Guo, T., et al. and Zou, P., et al. recently reported liquid chromatography-tandem mass spectrometry techniques of measuring DHEA in a sample by observation of mass transitions from a precursor ion with a mass to charge ratio of 271 to a fragment ion with a mass to charge ratio of 213, and a precursor ion with a mass to charge ratio of 289.2 to a fragment ion with a mass to charge ratio of 270.9, respectively.